An angular velocity sensor device includes a switch (S1) for selecting a first or second driving signal mutually opposite in phase applied to driving electrodes (D1, D2) to oscillate a weight part (8) in a first direction. An adding circuit (29) adjusts the amplitude of the driving signal selected and adds it to a monitor signal reflecting the oscillating state of the weight part (8). A noise signal component appearing in the output signal of the adding circuit (29) is adjusted to a minimum and the output signal is supplied as a feedback signal to a self-oscillating circuit (27) for reducing the noise signal influence on the oscillating drive of the weight part.
